Pete's right though. If you're going to have a MacGuffin in your adventure, it's pretty much guaranteed to be indestructible to anything less than being tossed into the fires of the volcano where it was forged, or something similarly epic.
Although that only guarantees that your players will somehow manage to find a lava-proof container and carry some of those fires around with them, just in case.
Ric Olié: It's blowing up from the inside! We didn't hit it!
Anakin: We need to get out of here. Where's the Orb?
R2-D2: If you wanted the Orb, why did we blow the ship up?
Anakin: You blew the ship up. You find it.
R2-D2: Fine. I do a multispectral scan. Any sign of it?
GM: You read a big power source.
GM: It's the Orb. It seems to be unharmed.
R2-D2: I fly over and grab it.
Obi-Wan: Terribly convenient how it survived an explosion that big...
R2-D2: It's the primary quest object of the entire campaign. Of course it's going to be indestructible.
GM: Stop metagaming.
R2-D2: Well how else could it possibly have survived?
GM: ...You fly over and grab it.